Project Summary/Abstract These experiments will further understanding about how and why child abuse leads to a broad range of mental and physical health problems. Although millions of children experience various forms of child abuse each year in the US, little is understood about how this experience influences brain-behavioral development. The General Aim of this research is to determine how environmental experience shapes neural circuitry in ways that lead to child mental health problems, and determine how these systems can be targeted to provide treatments for affected individuals. Here, we will test aspects of learning that might underlie problems in abused children. Once we identify a mechanism, we will advance our basic science to a pre-clinical space by determining if these mechanisms are responsive to laboratory manipulations. The Specific Aims are: (1) To specify the mechanisms affected by child abuse that lead to developmental changes in systems needed to effectively learn to communicate, interpret, and regulate emotion in the context of social interactions; (2) To determine which of these processes are most amenable to change through experimental manipulation. The proposed experiments combine neuroimaging, behavioral, and computational approaches to examine precise and novel questions about how experiences of child abuse are transformed into disruptions of the brain networks underlying emotional pathologies. This project: (1) Examines developmental change in children ages 8-14 years, covering critical pubertal transitions when many mental health problems emerge, (2) Probes discrete developmental mechanisms that can be targeted for intervention, (3) Is amply powered to properly test the hypotheses, (4) Characterizes aspects of relevant brain-behavior relationships are related to both RDoC dimensional constructs and DSM diagnoses, and (5) Employs sophisticated computational rigor to truly interrogate the critical questions under examination. Because child abuse is a powerful determinant of many subsequent mental health problems, the data generated from this project has profound implications for conceptualizing novel and more precise treatments for vulnerable children. It will do so by determining effects of chronic stress exposure on human neural circuitry early in development, when the brain may be particularly sensitive to environmental influences. The project moves away from description of risk groups to defining and specifying mechanistic ways in which the environment creates long-term effects on brain and behavior. These foci hold tremendous promise for advancement of knowledge and application to improvement of public health.